[HLSL][clang][Driver] Fix error when using the option -fcgl in --driv…

…er-mode=dxc. (#97001)

When -fcgl is set in --driver-mode=dxc, both -S and -emit-llvm are
currently enabled.

This results in the following error:
```
  error: '-S' action ignored; '-emit-llvm' action specified previously.
```
This change fixes the issue by not rendering -S in RenderHLSLOptions.

Additionally, a test has been added to ensure that enabling -fcgl does
not trigger any diagnostics

Fixes #97296

clang/lib/Driver/ToolChains/Clang.cpp

@@ -3666,7 +3666,6 @@ static void RenderHLSLOptions(const ArgList &Args, ArgStringList &CmdArgs,
   const unsigned ForwardedArguments[] = {options::OPT_dxil_validator_version,
                                          options::OPT_D,
                                          options::OPT_I,
-                                         options::OPT_S,
                                          options::OPT_O,
                                          options::OPT_emit_llvm,
                                          options::OPT_emit_obj,

clang/test/Driver/dxc_fcgl.hlsl

@@ -1,6 +1,9 @@
 // RUN: not %clang_dxc -fcgl -T lib_6_7 foo.hlsl -### %s 2>&1 | FileCheck %s
+// RUN: %clang_dxc -fcgl -T lib_6_7 %s -Xclang -verify
 
 // Make sure fcgl option flag which translated into "-emit-llvm" "-disable-llvm-passes".
-// CHECK:"-S"
-// CHECK-SAME:"-emit-llvm" "-disable-llvm-passes"
+// CHECK: "-emit-llvm"
+// CHECK-SAME: "-disable-llvm-passes"
 
+// Make sure fcgl option not generate any diagnostics.
+// expected-no-diagnostics